Climate: Factfile on the scienceCancun, Mexico (AFP) Nov 26, 2010 -
Following is a snapshot of scientific opinion on climate change ahead of the November 29-December 10 UN climate conference in Cancun, Mexico.

- Evidence for global warming is now unequivocal. There is a more than 90-percent probability that humans are the cause, mainly through "greenhouse" gases emitted by burning coal, oil and gas. These invisible carbon gases trap solar heat, thus warming up the atmosphere, land mass and oceans.

- Concentrations of carbon dioxide (CO2), the main greenhouse gas, reached 386.8 parts per million in 2009, up 38 percent from pre-industrial times. They are now at their highest in 650,000 years. CO2 has a strong inertial effect, meaning that emissions today will have an effect for centuries to come.

- Since 1900, the mean global atmospheric temperature has risen by 0.8 C (1.44 F) and the sea level by 10-20 centimetres (four to eight inches). The past decade was the warmest on record.

- Climate change is already visible, in the loss of alpine glaciers and snow cover, shrinking Arctic summer sea ice and thawing permafrost, changes in rainfall patterns, leading to flood and drought in many regions, and rising ocean temperatures.

- By 2100, global average surface temperatures could rise by between 1.1 C and 6.4 C (1.98 and 11.52 F) compared to 1980-99 levels. Within this range, common "best estimates" run from 2.4 C (4.3 F) for a scenario based on a major switch to non-fossil fuels to 4.0 C (7.8 F) for a fossil-fuel intensive economy.

- Intensifying water stress, dwindling agricultural yields and biodiversity, worse flooding from rainstorms and rising seas are among the potential impacts, depending on temperature rise. Mortality due to diseases associated with floods and droughts will increase. Tropical storms could become more vicious and/or more frequent.

- Scientists are also worried about several major unknowns in the climate equation. These include meltwater from the Antarctic and Greenland icesheets, which will affect sea levels, and "positive feedbacks," such as the release of methane trapped in Arctic latitudes, that could radically amplify warming.

- There is no consensus on what is considered a safe level of warming. To have a good chance of limiting it to 2C (3.6F), global emissions of greenhouse gases need to peak by 2020 at the latest, be more than halved by 2050 compared with their 1990 and continue to decline thereafter.

- The 2009 "Copenhagen Accord" set the target of limiting warming to 2C, but without specifying a roadmap for reaching it or making emissions pledges legally binding. According to an estimate by German scientists, current pledges mean there is a more-than 50 percent chance that warming will exceed 3 C (5.4 F) by 2100.

by Staff WritersCancun, Mexico (AFP) Nov 26, 2010 Global talks on climate change resume in the Mexican resort of Cancun on Monday, facing a clamour for results or the prospect of limbo.

The 12-day meeting climaxes an 11-month effort to pick up the pieces after last December's trauma in Copenhagen.

More than 120 leaders jetted to the Danish capital, expecting to bless a pact that would slow, halt and then reverse the threat to Earth's climate system.

Instead, they were plunged into a nightmare where they had to haggle over a horribly complex, fiercely disputed deal as the clock ticked away.

Face was saved by the "Copenhagen Accord," cobbled together by a couple of dozen leaders, setting an aim of limiting warming to two degrees Celsius (3.6 degrees Fahrenheit) but lacking key details about how to achieve it.

Shocked and widely ridiculed, the 194 parties to the UN Framework Convention on Climate Change (UNFCCC) have since then taken a low-key, unfailingly pragmatic tack. In a sign thereof, Cancun will end with talks at ministerial level, not heads of state or government.

"One of the things that is at stake in Cancun is the legitimacy and credibility of the UN process," said Elliot Diringer of the US thinktank, the Pew Center on Global Climate Change.

"If you have a second failure in the process, you may see parties start to withdraw from the process. I don't mean from the (UN Framework) Convention (on Climate Change), but to begin to look elsewhere for making progress."

Frustrated by the snail's pace and labyrinthine meanderings, countries could be lured by smaller, nimbler fora such as the G20, he said.

They could also be tempted to launch sectoral negotiations that cover specific carbon-spewing industries, such as power, transport and steelmaking.

In the new post-Copenhagen age, there is no expectation of sealing a post-2012 treaty in Cancun, and talk of wrapping it all up in South Africa at the end of 2011 has also been sidelined.

Indeed, bolder minds do not even want to pronounce the "T" word, given the task of stitching together an all-embracing treaty stuffed with so many connected issues, with every risk that it could be unravelled by national interests.

Instead, the new approach is to secure visible progress on separate operational issues and then ratchet up these measures, bit by bit, in successive rounds of talks.

"One of the big lessons from Copenhagen that countries have actually learned from themselves is that there is no such thing as one all-encompassing solution," UNFCCC Executive Secretary Christiana Figueres told reporters this month.

"They also seem to be setting out to develop the building blocks upon which they can build realistic action on the ground, because countries really need results on the ground right now."

A European negotiator said the new credo was "bottom up" (progress on the ground) as opposed to "top down," or a treaty.

"There are big weaknesses in it, but it's political reality and we have to deal with it," he said.

Cancun could unlock action in several important areas, he said.

The one likeliest to make headlines is the launch, even symbolic, of a so-called "Green Fund" to help poor, climate-vulnerable countries.

It could be the main vehicle for aid, promised by rich countries in Copenhagen, that could reach as much as 100 billion dollars a year by 2020.

Another area of progress is a deal on financial help to prevent tropical deforestation. Logging and conversion of forests to agriculture or habitation accounts for 12 percent of greenhouse-gas emissions.

The prospects for dealmaking remain troubled, though, by tensions between China and the United States, the world's No 1. and No. 2 emitters, who between them account for 41 percent of all fossil-fuel carbon pollution.

China is irked by US demands to submit its emissions pledges to international scrutiny, even though Washington's own emissions plans are unambitious and at threat from conservatives in Congress.

At UNFCCC talks in Tianjin in October, China's chief climate negotiator, Su Wei, likened the US stance to "a pig looking in a mirror" and finding itself beautiful.

"Both the US and China are doing their best that in the event of a failure, it will be the other who gets blamed," said Diringer.

UN body warns Copenhagen climate targets could be missedHelsinki (AFP) Nov 23, 2010
The Copenhagen accord targets to cut global warming will be missed unless next week's climate change conference transforms promises into action, the United Nations Environment Programme (UNEP) said Tuesday.
Representatives from 194 countries meet in the Mexican resort city of Cancun from November 29 to December 10 for a new bid to strike a deal to curb greenhouse gases following on last Dece ... read more

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